"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

There are a lot of books out there (I have about 20 of them;)) For regexp I found the Programming Perl (O'Reiily) and the Perl Developers Guide from Osbourne Press the best. The important thing to remember is that:
1. The easiest way to learn is by doing, tackling real problems and trying to figure out if this script can do this how can I make it do that, etc.
2. The answer will never be in one single book or website. When I am looking for someting I always have 3 or 4 books open in front of me and another few tossed to the floor (well not literally) and a bunch of websites opened. BEst is to develop your own little library, in the bookstore look inside and see if you can understand easy the thought-process of the book before you buy it.

If you don't understand / get something or something does not work as it supposed to be, against all logic (it happens) just log on and shoot off a question or search the already answered questions. These guys have helped me more times than I can count.